Riveting apparatus



Oct. 22, 940. E BECKER 2,218,805

RIVETING APPARATUS Filed 001;. 5, 1938 2 Sheets-Sheet l "IIIIIIIIA EM/LBECKER INVE/VTUR Arron/var Oct. 22, 1940. E. BECKER RIVETING APPARATUS Filed Oct. 5, 1938 2 SheetsShee1 2 25 [MIL BECKER-IN VEN TOR A TTORNE y Patented Oct. 22, 1940 UNITED STATES I 2,218,805 RIVETING APPARATUS- Emil Becker, Munich, Germany Application October 5, 1938, Serial No.- 233,406

I In Germany November 14, 1932 3 Claims. (01. 78-51) The invention relates to a method of and apparatus for riveting and is particularly suitable for the manufacture of hollow products of high quality made from comparatively thin sheet metal.

Heretofore, the joining of the walls of hollow structures from thin sheet metal by riveting had the disadvantage that the interior stresses in the sheets caused by the deformation of the rivet tends to buckle and separate the sheets between two rivets. A distinct disadvantage of the customary riveting process employing rivets of rather large diameter and spaced far apart is the fact that the stresses to be transmitted from one member on the riveted structure to the other are concentrated at a few points of connection, thus unduly stressing the small cross-sectional area of the thin sheets. According to the invention rivets of such small diameter are used that they do not harm the surface of the sheets and that only small stresses are transmitted at each point of connection. The required total strength of the structure is obtained by increasing the number of the rivets correspondingly. As far as the evenness of the distance of the stresses is concerned, this method approaches very closely welding or seaming. In order to assure economy of the process and obtain at the same time a smooth surface this process employs headless riveting pins which are inserted from the outside and counter-sunk. Where a smooth surface is not necessarily required, ordinary rivets may be used which are also inserted from the outside.

A further feature of the invention is the method of controlling the movement of the anvil during riveting. In the manufacture of hollow structures, this is accomplished by applying a constant force on the anvil urging it to move in the desired direction. However, movement of the anvil is restrained by the rivets, the anvil being so shaped that as the rivets shorten in length during riveting the anvil is allowed to move to a new position.

Other and further advantages of the invention will be apparent from the following description and the accompanying drawings, in which:

Figure 1 is a cross-sectional view on the line I --I, Figure 2.

Figure 2 is a cross-sectional view on the line 2-2, Figure 1.

Figure 3 is a cross-sectional View similar to Figure 2, showing an alternative construction of the anvil.

Figure 4 is a side elevation, partly in section, showing another construction of the anvil.

Figure 5 ma cross-sectional view on line 5-5, Figure 4.

Figure 6 illustrates one method of guiding the anvil during riveting.

Figure 7 shows a further modification of the anvil illustrated in Figures 1 and 2.

Figure 8 illustrates one method of moving the anvil during riveting.

Figure 9 illustrates a modification where the anvil is held stationary and the work is moved during riveting.

Figure 10 illustrates a further modification of the invention.

Like characters of reference refer to like parts throughout the specification and drawings.

In Figure 1, I indicates a sheet of metal to be riveted to part, 2 which in the present case is a U-channel. The sheet and the U-channel are united by the rivet 3 which at the start of the riveting operation is a headless pin of small modification is shown consisting of a recess 5 having an inclined surface 8. The recess 5 is of such depth that when pin 3 rests on the bottom surface 6 of the recess 5, the pin will protrude out of the work far enough to fill the counter-sink 1 when riveted over and also allow for enough material to form the interior head. By some suitable means such as weights, springs, or manual or mechanical force applied to the anvil 4 it is urged or moved in the direction indicated by the arrow in Figures 2 and 3. However, movement of the anvil is restrained or prevented by the pins 3.

After the first few blows the diameter of the rivet has increased sufiiciently to hold the pin securely in the hole. As the riveting progresses, the anvil moves causing the lower end of the pin to remain in contact with the inclined surface 8 as the shortening of the pin proceeds. In this manner both heads are formed simultaneously. The finished position is shown in Figure 2, wherein completed rivet 3 is shown as having its lower head in the space between the work and the top surface of the anvil. The anvil is maintained at the correct distance 9 from the work by means of the distance piece similar to the distance piece l3 shown in Figure 4. In Figure 3 is also shown an arrangement when using rivets in which case it is advisable to use a rivetingset In with a recess ll corresponding to the shape of the head. Figure 7' also shows a modification of the anvil 4 shown in Figures 1 and 2.

When riveting hollow structures with channels as inner stifieners as indicated by l2 in Figure 5, made from thin sheet metal, it is very disadvantageous for the quality of the riveting if the height of the channels varies. It is therefore necessary that the distance between the anvil and the work as well as the length of the pin and the depth of the counter-sink are maintained constant to get uniformity in riveting. Since it is difficult and expensive to produce channels of exactly uniform width, it has been necessary to devise an anvil which will automatically adjust itself to the irregularities in the width of the channels and maintain the correct spacing between the top of the anvil and the work.

According to one modification of the invention the anvil is provided with distance pieces I3 and a lever mechanism l4 which presses the anvil upwardly so that the distance pieces are constantly in contact with the inner surface of the work. Figures 4 and 5 illustrate such anvil as actually used. I5 is a spring pressing lever [4 with its roller l6 downwardly thereby maintaining the roller in constant engagement with the bottom of the channel. H are pins to hold the spring and I8 is a hook to attach a rope or other means for moving the anvil. This construction is such that lever M with its roller l9 will not yield to the blows of the riveting hammer but is adapted to follow irregularities in the width of the channel and thus maintain correct spacing between the top of the anvil and the work. The distance pieces l3 may be rollers, pins, cams, or other protrusions maintaining the distance 9 and may preferably be made adjustable. It is advisable to locate the distance pieces out of the line of rivets so that they will not interfere with the rivet heads.

It has been found to be extremely advantageous to equip the work with guides for the anvil, that is, U-channels or angles IS in Figure 5, or shapes as shown at 20 in Figure 6. In this way standardized anvils may be used in the production of all kinds of shapes of structures.

To move the anvil along as the riveting progresses, gravity or permanent acting forces such as weights 2! in Figure 8 or springs may be employed in place of weights. In this case one man can do the riveting extremely rapidly.

Figure 9 illustrates a case where the anvil remains stationary while the work is moved as the riveting progresses. l and 2 indicate the work, 4 the anvil which is held by rod 22 which in turn is fastened to wall 23. The work rests on table 24 which is movably mounted on bench 25.

Figure shows an arrangement in which the riveting is done by a machine. Ram 26 presses the rivets to a small extent at each stroke while by the upward movement of the ram the work is carried forward far enough to again establish contact between the inner rivet heads and the anvil which is held stationary by rod 22.

With the process embodied in this invention it is possible to economically employ a large number of rivets of small diameter thus avoiding interior stresses in the thin sheets to be joined and therefore obtaining liquid and gas proof joints without caulking and smooth surfaces free from wrinkles and counter-sunk rivets if rcquired. With this process structures'of refined design and light weight in connection with extreme strength can be produced economically'as this process does not injure the corrosion resistant coating which may be applied to the material before fabricating. This eliminates the necessity of employing non-corrosive expensive materials.

What I claim as my invention is:

1. An anvil for use in riveting joints of hollow bodies comprising a solid mass adapted to slidably fit inside said body, said mass having a sloping face against which the heads of rivets inserted from the outside of the body are formed,

a swingable lever pivotally secured to the mass and having its free end inclined and engaging the inner face of the hollow body opposite the face being riveted, means for changing the inclination of said lever to move the mass towards the inner face of the portion of the hollow body being riveted, means for moving said mass, step by step, parallel with the joint as the shortening of the rivet progresses during riveting until the inside head of the rivet is completely formed, and distance pieces projecting upwardly from the rivet engaging face of the mass and adapted to engage the inner face of the portion of the hollow body being riveted and retain the mass a predetermined distance from the said inner face of the hollow body.

2. An anvil for use in riveting joints of hollow bodies comprising a solid mass adapted to slidably fit inside said body, said mass having a sloping face against which the heads of rivets inserted from the outside of the body are formed, a swingable lever pivotally secured to the mass and having its free end inclined and engaging the inner face of the hollow body opposite the face being riveted, means for changing the inclination of said lever to move the mass towards the inner face of the portion of the hollow body being riveted, means for moving said mass, step by step, parallel with the joint as the shortening of the rivet progresses during riveting until the inside head of the rivet is completely formed, and rollers projecting upwardly from the rivet engaging face of the mass and adapted to engage the inner face of the portion of the hollow body being riveted and retain the mass a predetermined distance from the said inner face of the hollow body.

3. An anvil for use in riveting joints of hollow bodies comprising a solid mass adapted to slidably fit inside said body, said mass having a sloping face against which the heads .of rivets inserted from the outside of the body are formed, a swingable lever pivotally secured to the mass and having its free end inclined and engaging the inner face of the hollow both! opposite the face being riveted, means for changing the inclination of said lever to move the mass to- Wards the inner face of the portion of the hollow body being riveted, means for moving said mass, step by step, parallel to the joint as the shortening of the rivet progresses during riveting until the inside head of the rivet is completely formed, and rollers adjustably projecting upwardly from the rivet engaging face of the mass and adapted L0 engage the inner face of the portion of the hollow body being riveted and retain the mass a predetermined distance from the said inner face of the hollow body.

EMIL BECIER. 

